Transcript for Dressed to Impress: America Watches First Lady for Fashion Hints

But this is, in so many ways also the second inauguration for mrs. Obama, who has been such a force in american life for obtaining jobs for military families. Such a force for health and nutrition for american children. But she also has to contend with something else. The scrutiny of those clothes. And tonight, we try to answer the question -- why does everyone pay so much attention? Abc's deborah roberts explains. Reporter: Michelle obama dazzled in a navy blue silk coat by a little known american, thom browne, who only learned his design was chosen when he saw it today. I know she had a lot of other people that she could have, you know, chosen from and to be the one that she chose is one of those amazingly humbling experiences. Reporter: Browne, best known for men's, not ladies wear, could benefit from the first lady's midas touch. Any time mrs. Obama waerms one of your designs, a fashion descender ascends. It's a phenomenal career maker. Reporter: It's that $14 million boost for any designer she wears. And the steady profits she delivers to the mass market brands she mixes in with couture choices. J crew, a first family favorite, made that sparkly belt and purple cloves she wore with that coat today. First daughter malia, also in j crew. Sister sasha in kate spade. But the best may be yet to come tonight. Will the first lady top that flowing jason woo she wore back in 2009? One lucky designer will find out shortly. And rest assured, the phone will likely be ringing off the hook, maybe as soon as tonight. And I can only imagine, maybe with orders being played by morning. Fashion watchers say that michelle obama is so accessible that women just want to dress like her, diane. So, we're going to hear a lot more about it, I'm sure, tomorrow.

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